In recent years, with rapid development and wide applications of information technology and data technology, the data storage technology is improved quickly in accordance with Moore's Law, of which changes on the innovation of storage medium, expansion of storage capacity and storage mode are representative.
At present, various storage cards including SM card, CF card, MMC card and SD card, etc., are based on Flash Memory as medium, and are widely applied to digital equipments, such as digital camera, digital video, etc., as a storage device, due to its reliability of performance and expandability. However, such a storage device or storage medium has clear shortcomings, which exist clearly in the following aspects:
1) Small storage capacity. The capacity of various storage cards existing in the market currently includes 16M, 32M, 64M and 128M, while the storage cards up to the capacity level of gigabytes “GB” are costly, and therefore are unacceptable for ordinary consumers. The number of files of digital photo or picture stored in storage medium of megabytes is very limited. For example, when a SM storage card of 16 M is used to store digital photos or pictures, only four can be stored using SHQ format with a resolution of 2560×1920 pixels, only ten can be stored using HQ format with a resolution of 2560×1920 pixels, and only one photo or picture can be stored using TIFP format with a resolution of 2560×1920 pixels.
2) Limitation of occasions of using such a storage card. A storage card is a passive storage device, and must be connected to a computer as the data processing system for operations of write and read performance on the storage card. On occasions where carrying a computer may be inconvenient or no computer is available, the storage card cannot be used at all, and thus the usability thereof is low.
3) Card specialty and incompatibility. Due to the different standards adopted by different digital equipment manufactures and different interface standards of computers, an interface converter (e.g. card reader) must be required to perform data conversion between interfaces when these computers are connected to process data. In this case, if a plurality of different types of storage cards are desired, the user may need multiple card readers, and therefore, the cost of devices is high, and operation is complicated.